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authorNeilBrown <neilb@suse.de>2013-06-11 15:08:03 +1000
committerNeilBrown <neilb@suse.de>2013-06-14 08:10:27 +1000
commit725d6e579f06360744fc101b1af2f82d8aa282f1 (patch)
treec46f6b92ac05727d1201f6f63276dfeb6ddd4096 /drivers/md
parent635f6416a2e983adac8ccf90bffbeed0c1a76454 (diff)
md/raid10: check In_sync flag in 'enough()'.
It isn't really enough to check that the rdev is present, we need to also be sure that the device is still In_sync. Doing this requires using rcu_dereference to access the rdev, and holding the rcu_read_lock() to ensure the rdev doesn't disappear while we look at it. Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/raid10.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 5169ed2a9156..aa8ba0760cac 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1633,6 +1633,7 @@ static void status(struct seq_file *seq, struct mddev *mddev)
static int _enough(struct r10conf *conf, int previous, int ignore)
{
int first = 0;
+ int has_enough = 0;
int disks, ncopies;
if (previous) {
disks = conf->prev.raid_disks;
@@ -1642,21 +1643,27 @@ static int _enough(struct r10conf *conf, int previous, int ignore)
ncopies = conf->geo.near_copies;
}
+ rcu_read_lock();
do {
int n = conf->copies;
int cnt = 0;
int this = first;
while (n--) {
- if (conf->mirrors[this].rdev &&
- this != ignore)
+ struct md_rdev *rdev;
+ if (this != ignore &&
+ (rdev = rcu_dereference(conf->mirrors[this].rdev)) &&
+ test_bit(In_sync, &rdev->flags))
cnt++;
this = (this+1) % disks;
}
if (cnt == 0)
- return 0;
+ goto out;
first = (first + ncopies) % disks;
} while (first != 0);
- return 1;
+ has_enough = 1;
+out:
+ rcu_read_unlock();
+ return has_enough;
}
static int enough(struct r10conf *conf, int ignore)